On levels that have Bobs in them, the Bobs frequently get stuck - jammed together in narrow hallways and such, blocking them. On levels such as The Rose (Marathon 1) where your mission is to keep as many from being killed as possible, it's kind of counterproductive to kill the Bobs to get them out of the way; but if they're blocking the door to an important comm terminal then sometimes there's no choice but to kill them.

Is there any way to 'prod' a Bob to move in the other direction without hurting or killing him?